New Edge for Blade Servers

Blade servers offer a way to pack lots of processors into a small space. Estimate whether you want to make the leap.

Blade servers, which pack more processing power into less space than conventional servers, are attracting increased interest among technology managers. Why? They are cheaper, more powerful and more flexible compared to blade servers sold even one year ago.

30 kilowatts in only 3 square feet of floor space. While 30 kilowatts isn't a huge amount for a large server room, it's a lot for a single rack. The practical way to keep equipment cool is to use water, not air, pumped in from a chiller. Blade server vendor Egenera uses a coolant, so a leak produces only gas, not liquid.

The weight of a loaded rack can crush floors; 3,000 pounds in a 19-inch-wide rack will produce a floor loading of about 1,000 pounds per square foot. Standard racks have a 2,500-pound limit, half that if the racks are on rollers. Budget for new racks, if necessary.

The cost for blade server enclosures can add up. For example, Dell's 10-blade PowerEdge enclosurewithout any bladesis $3,000. So, plan the installation with enclosures well populated. Dell estimates that an enclosure with five blades costs about the same as five single-RU (rack unit, equivalent to about 1.75 inches) rack-mounted computers using the same CPUs. Depending on the vendor, enclosures may hold two to 30 blades.